Twin compound marine steam engine



April 27 1926.

H. LENTZ TWIN COMPOUND MARINE STEAM ENGINE Filed Sept. 29, 1920 4 Sheets-Sheet 1 Fig.1.

April 27 1926.

$582,410 H. LENTZ 'TWIN COMPOUND MARINE STEAM ENGINE Filed Sept. 29 1920 4 Sheets-Sheet 2 Apfil 27 1926. I 1,5 2 410 H. LENTZ TWIN COMPOUND MARINE STEAM ENGINE Filed Sept. 29, 1920 4 Sheets-Sheet 5" Fig.3. 3

In vehtor April 27, 1926.

H. LENTZ TWIN COMPOUND MARINE STEAM ENGINE 4 Sheets-Sheet 4 Filed Sept. 29 1920 1/7 venfor:

'a u Z "5- Patented Apr. 27, 1926.

* insane NITED STATES PATE i I HUGO LENTZ, OF MAUEB, NEAR VIENNA, AUSTRIA,

4 TWIN COMPOUND MARINE STEAM ENGIN Application filed September 29, 1920. Serial No. 413,656.

7 following is a specification.

' ing shown in section.

This invention relates to a twin-compound marine steam engine, in which the cranks of one compound engine are'displaced 90 with regard to the cranksof the other compound engine, the cranks of thehigh-and low-pres surecylinders of each compound engine being displaced 180 the one with regardto the other, the exhaust valve of the high-pressure cylinder forming at the same time the inlet valve of the'low-pressure cylinder according to VVoolfs principle, so that no receiver is required. In order to ensure the most profitable steam distribution the high-pressure cylinders are preferably arranged in the middle, the low-pressure cylinders being situated at the sides. l/Vith each compound engine an eccentric and lay shafts are connected for the simultaneous control of all the valves of each engine. The two reversing links can be made in one piece according to this improved form. of construction, so that the reversing gear not only becomes simpler but is more accessible for repairs.

In the drawings Fig. 1 is the front proved engine.

Fig. l is a plan view of thejcrank shaft of the engine shown in Fig.1., h

Fig. 2 is a side elevation of the engine.

Fig. 3 is a plan view, the middle part beelevation of an im.

.Fig. 3 is a vertical section through one of the high-pressure cylinders and the corresponding reversing gear ing the inlet valves. 3

Fig. 4: shows the valve operatingand rcvol-sing mechanism of one compound engine on a larger scale in side elevation, the position of the reversing mechamsm oi the other compound engine being indicated by dotted centre lines.

Fig. 5 is a. front elevation of the link in section on line V-V of Fig. 4: and seen in casing conipris- The engine consists of the two high-pressure cylinders 1, l and of the two low-pressure cylinders 2, 2 which, by means of the standards 3 and supports 4, are mounted upon the bed plate 5. The high-pressure cyllnders 1, 1 are situated advantageouslyv at the middle and the low-pressure cylinders 2, 2 atthe sides. The crank shaft 6mounted in the bed plate is driven from the several cylinders by means of connecting rods 7 1n the manner usual with vertical marine steam engines. Onehigh-pressure cylinder and one low-pressure cylinder form together ponnd'being displaced 180 the one to the other (Fig. 1). a I 1 i The link motion of each of these compound engines isoperated by single eccentrics 8, 8 respectively, shown in full and dotted lineson Fig. 4, which are keyed upon the crank shaft (5 near the middle. An ec-. centric rod 10 attached to the eccentric strap 9 which surrounds the eccentric 8, has a pin 11 at the middle upon which a sliding block 12 is mounted which slides in the link 13. The oscillating lay-shaft 31is driven iron.

the eccentric rod 10 by means of a connect ing rod 15 mountedupon a pin .14; fixed in the end of sa d individual eccentrlc rod 10. Fig. 4 shows the described reversing mechanism of one compound engine. The position of the reversing mechanism of the other compound engine, which is not visible on the drawing, is indicated in dotted centre lines.

Each of the two compound engines is provided with an eccentricdrive for the control of the inlet valves 33 the intermediate valves 34 betweenhigh-pressure and low-pressure the middle of the engine. The corresponding links 13 are made in one piece with the link shaft 16 (Fi 5). The inner. guide faces 17' of the said links are cylindrically formed and serve as guides for the correspondingly formed sliding blocks 12 inserted from the side. -The sliding blocks are thus secured against giving; wayin lateral direcuse, the. jammin of Said sl ding blocks which may be predncd through the cancer ronce of the forces upon theeccentric rod being thus avoided as the sliding block may adjust itself to the corresponding'angle in the cylindrical guide.

The link shaft 16 can be oscillated in the bearings 18 IDOUlItGClUPOIl the middle support of the bed plate 5. lVith this object in view a lever 19 is fixed at the middle of the link-shaft and carries at its end a nut 21 adapted to oscillate in a fork around the pin 20. This nut can be displaced bythe handwheel 22 by means of a'spindle 28, the lever 19 being thus brought to the proper position for the desired direction of rotation of the engine. The spindle 23 is mounted 'in a bearing25 adapted to pivot around the pin 26 in a fork-shaped part of the column 2st fixed upon the bed plate 5.

hen the crank shaft 6 revolves the connecting rods 15 are operated by'the eccentrics, said connecting rods actuating the guide rods 28 mounted in the transverse guide bars 27 fixed between the two middle columns 4 of the engine; each of, said guide rods 28 t ansmitting, through the intermediary of a connecting rod 29 and of a lever 30, an oscillating-motion to the lay shafts 31 of either side of the engine. The cams 32, 32 and 32 required for the operation of the valves of each compound engine indicated in dotted lines'in Figs. 1 and 2," are mounted upon said lay shafts.

Fig. 6 shows a diagram of the valve .gear in the positionfor the forward motion ofthe engine. For clearness sake the diagram is shown for infinite length of connecting rods as shown in the figures and onlyfor-the'top side of the cylinders. The operation of the valve gear is then as follows In the drawn-out position of the crank the high-pressure crank stands according tothe position a of the centre of the eccentric,

which is always displaced 180 oppositely to the position of the crank, in a position just before the upper dead centre is reached, the pint} being in the position a. The cam 32 or the'inlet valve of the high-pressure cylinder is about to lift the roller and to open thus the'inlet valve. Upon further rotation the high pressure crank reaches the upper dead centre position so that the centre of the eccentric attains the position Z) and the pin 14 the position 7); the inlet va-lve'is'now open. In the succeeding position 0 of pin 1%, the inlet valve is completely-openedand now the direction of the lay shaft 31 is being reversed. WVhen'the rotation of the crank shaft continues, the inlet valve begins to close and is closed in position (5' according to the position d of-the centre of the eccen tric, the steam admission to the high-pressure cylinder being terminated. This is cut off. Now the-expansion in the high pressure cylinder begins which continues until the pin let arrives at the position 0" and the 'tothe low-pressure cylinder the crank oi the lattcr has'arrived in the meantime in close proximity to the upper dead centre.

At the succeedin Joint the low-'n'essure a piston 15 at the upper dead centre and the 'high-pressln'e piston is at the lower dead centre. Points g, g designate the lower reversing position of the connecing rod 15. In thisposition the intermediary valve is completely opened by'the cam 32. This is exhaust for the high-pressure cylinder and admission for the low-pressure cylin der and this valve closes again when pin M reaches posit-ion h. In the high-pressure cylindertlie compression beginsand continues and in the low-pressure cylinderthe admission is terminated at the same time and the: expansion begins. In the position 1?, cam 3'1, opens the low pressure'outlet valve so that the steam may escape to the condenser or into the atmosphere. 'iVhen the'rotation continues, tlifillCXt'ilCllDlSSlOIl to the highpressure cylinder takes place from point a to (Z, but the steam escape from'the low-pressure'cylinder is terminatedonly at point 7; by the closing of theoutlet valveyand'the compression begins which continues until at point e the admission of the steam from the high-pressure cylinder begins again as above described.

For back-motion the'operation is the-same with theexception thatpin H-describes a curve which is displaced with regard to the curve for forward motion and inclined to the right. The'several points correspond 'ing to the-backward motion are here designated by bred.

In comparison with-the marine-steam engines of usual constructi m which comprises a separate link for each steam cylinderycach link being mounted upon. a separate shaft or upon a separate pin, themarino steam engine of the improvedconstruction described prcscnts-the'advantage that the distributing arrangement can be constructed in a, very simple and compact manner. Owing to the simplification of the valveagear the adjusting of the link motion becomes more exact and much easier.

I claim 1. In a marines.cam-engine comprising in combination two units each of one compound engine, a lay shaftfor each unit, a re versing gear for both units situated at the middle of the two units, one eccentric at each side of the reversing gear, rods for connecting said eccentrics with the lay shaft of each unit adapted to operate said lay shaft, and cams on each lay shaft for operating the valves in each of the compound en gines.

2. In a marine-steam-engine comprising pound engine, a lay shaft for each unit, a rcversing gear for both units situated at the middle of the two units consisting of one link for each compound engine, of a shaft connecting the two links and of means for adjusting said shaft, one eccentric at each side of the reversing gear, rods for connecting said eccentrics with the lay shaft of each unit adapted to operate said shaft, and cams on each lay shaft for operating the valves in each of the compound engines.

' 3. In a n1arinesteam-engine comprising in combination two units each of one compound engine, a lay shaft for each unit, a

- guides, a shaft connecting the two links and means for adjusting said shaft, one eccentric at each side of the reversing gear, rods for connecting said eccentrics with the lay shaft of each unit adapted to operate said lay shaft, and cams on each lay shaft for operating the Valves ineach of the compound engines.

In testimony whereof I affix my signature.

HUGO LENTZ. 

